1. Field of the Invention
This invention relates to theft-thwarting devices to help prevent the loss of shopping carts from shopping stores. The invention disables operation of the front wheels of the cart as well as the rear wheels, and keeps the cart from being pushed out of the parking lot once the front wheels of the cart are disabled.
2. Description of Related Art
Millions of dollars are lost each year by grocery stores and shopping marts as a result of shopping cart theft. The expenses associated with shopping cart theft include cart replacement (with typical costs ranging from $55 to $85 per cart) and costs for retrieval of carts taken off the premises.
In applicants' co-pending application, a shopping cart having novel anti-theft features was disclosed and claimed. In particular, the invention in that application addressed the problem of improper removal of shopping carts from the store's premises, and proposed as a solution a disabling apparatus comprising a combination of structural features borne by the basket supporting frame of the cart to render the cart's wheels inoperative upon actuation of the disabling apparatus. The object of the invention was to make it extremely difficult for a person having the intent to remove the cart from the store's premises by rolling it away.
The present invention is drawn to improvements over the previously presented subject matter, and incorporates additional shopping cart theft thwarting features. One major objective of the present invention is to defeat shopping cart theft attempts where the wheels of the shopping cart have been disabled but the thief still tries to remove the cart from the premises by tipping the cart so that the disabled wheels are removed from contact with the ground. In this way, the thief can then wheel the cart away on two wheels.
In response to the obvious need for a theft proof cart, several types of anti-theft devices for shopping carts have previously been developed. For example, U.S. Pat. No. 3,717,225 to Rashbaum (1973) discloses a piston rod and wheel lock device. This device includes a frame mounted actuator that locks one of the wheels of the cart. It does not eliminate the potential for the use of one bank of cart wheels rotating by lifting the disabled wheel from the contact with the ground. U.S. Pat. No. 5,315,290 to Moreno (1994) discloses an electronic wheel lock device. This device also fails to eliminate the possibility of leaning the cart to the side of the still active wheels. U.S. Pat. No. 4,2422,668 to Herzog (1980) discloses a collapsible sub frame causing the wheels to swing out of operative position. This device immobilizes the front wheels of the cart, but does not eliminate the possibility the cart can be leaned back, and rolled away using the rear wheels of the cart. U.S. Pat. No. 5,357,182 to Wolfe et al. (1994) discloses a braked wheel device. This device also fails to eliminate the possibility of leaning the cart to the side of the still active wheels once the cart has left the boundary of the parking lot. U.S. Pat. No. 4,524,985 to Drake (1985) discloses an arrest device for a wheeled cart, which relies on a hooking device in the parking lot, but does not appear to eliminate the possibility that the cart could be leaned to one side to avoid the hooking device. Similarly, U.S. Pat. No. 5,576,691 to Coaklet et al. (1996) discloses another form of a wheel locking device that also fails to prevent the removal of the cart by a user who can simply tip the cart onto its back wheels and roll the cart away. U.S. Pat. No. 4,577.880 to Bianco (1986) discloses still another form of a wheel locking device that fails to eliminate the removal of the cart by simply tipping the cart on to the back wheels and rolling the cart away. U.S. Pat. No. 4,772,880 to Goldstein (1988) discloses another form of the wheel locking device, disabling only one of the front wheels. U.S. Pat. No. 5,194,844 to Zelda (1993) discloses a proximity wheel locking mechanism. This device also fails to eliminate the removal of the cart by simply tipping the cart on to the back wheels and rolling the cart away. U.S. Pat. No. 4,591,175 to Upton (1986) discloses a magnetic wheel locking mechanism. This device also fails to eliminate the removal of the cart by simply tipping the cart on to the back wheels and rolling the cart away.
Many of the devices disclosed by these patents demonstrate that disabling only one wheel of a shopping cart is insufficient to completely immobilize the cart, for even if one wheel is disabled, the person removing the cart can continue to push the cart with sufficient force to override the traction of the locked wheel. Moreover, a shopping cart of the Herzog design, in which the two wheels of the front wheel assembly were disabled by allowing the sub frame of the cart to collapse around the front wheel assembly, failed to prevent the leaning of the cart backwards over, and rolling it away on, its rear wheels.
None of these previously known devices totally disables the cart. If one wheel is locked, a person intent on removing the cart from the premises can exert enough force to overcome the friction of the locked wheel. None of the devices heretofore known can prevent all the wheels of the cart from being disabled. If two wheels are disabled, as is taught by the Herzog patent, the cart can still be maneuvered by tilting the cart so that it can still be rolled away.